Syria’s regime unleashed tank fire and air strikes on rebels on Wednesday as it slammed France for recognising an opposition bloc formed in Qatar that it said amounted to a “declaration of war”.

Tanks shelled two Palestinian refugee camps in the opposition bastion of southern Damascus, while fighter jets bombed Maaret al-Numan, a town near Turkey that rebels captured last month, a watchdog said.

But rebels killed at least 18 soldiers as they overran a military post near Ras al-Ain, a town also on the Turkish border that the armed opposition seized Friday, said the Syrian Observatory for Human Rights.

A day after France became the first Western nation to recognise the newly united opposition, Damascus hit out at the decision and said the Qatar meeting at which the dissident factions united on Sunday amounted to a war declaration.

“The Doha meeting was a declaration of war. These people (the opposition) don’t want to solve the issue peacefully through the mechanisms of the UN,” Syria’s deputy foreign minister, Faisal Muqdad, told AFP.

“We read the Doha document and they reject any dialogue with the government.”

Reacting to the French move, Muqdad said: “Allow me to use the word, this is an immoral position. They are supporting killers, terrorists and they are encouraging the destruction of Syria.”

Prime Minister Dmitry Medvedev of Russia, a strong Damascus ally, also criticised countries siding with the opposition and insisted Moscow was staying neutral.

“We don’t support anybody in this conflict, neither President (Bashar al-) Assad nor the rebels… but unfortunately, the point of view of some states is more one-sided,” Medvedev told Finnish newspaper Helsingin Sanomat.